The present invention relates essentially to a method of manufacturing pipes and in particular compound tubes for conveying or carrying various materials or fluids of any kinds.
It is also directed to a pipe or tube obtained through this method.
There are already known tubes or pipes made from glass fibers and resin, these tubes being insertable and inflatable or expandable in a damaged pipeline with the purpose of lining and thereby restoring the inner wall of this pipeline. This kind of tubes or pipes is made from compound sheet materials the edges of which are welded or sewn or stitched thereby imparting a weakness to the tubes at the line of seam or weld. In other words, upon inflating or expanding the tube or pipe, the latter would necessarily exhibit weak spots along a line corresponding to a generating line of the tube. Moreover, this kind of tube once positioned inside of the pipeline and lining or facing its inner wall would constitute a somewhat lost tube. In other words, it may not be recovered for carrying out for instance the inner lining or facing of another pipeline after repair of the pipeline provisionally containing the tube.
Furthermore, there are long known rigid tubes or stiff pipelines made from polyvinyl chloride for instance which are used for carrying or conveying various gases or liquids. These tubes however while being rigid and strong, i.e. without any weak spot, may not be used as a provisional or final inner lining or facing of damaged pipelines.